In general, a flat panel display device such as PDP or LCD is equipped with an anti-reflective film to minimize the reflection of light made incident from the outside.
As a method for minimizing the reflection of light, a method of dispersing a filler such as inorganic fine particle to a resin and coating the filler on a substrate film to impart irregularities (anti-glare: AG coating); a method of utilizing an interference of light by forming a plurality of layers having refractive indexes different from each other on a substrate film (anti-reflection: AR coating); or a method of utilizing a combination thereof have been known.
Among them, in case of the AG coating, the absolute amount of the reflected light is a level equivalent to a conventional hard coating, but a low-reflection effect can be obtained by reducing the amount of light entering the eye using the scattering of light through the irregularities. However, in the AG coating, the screen resolution degrades due to surface irregularities. Thus, in recent years, many studies have been made about the AR coating.
As the film using the AR coating, those having a multilayer structure wherein a hard coating layer (high refractive index layer), a low-reflection coating layer or the like are laminated on a substrate film have been commercialized. However, a method of forming a plurality of layers as described above has a drawback that as the steps of forming the respective layers are separately performed, the interlayer adhesion (interfacial adhesion) is weakened, and thereby the scratch resistance is poor and the production cost is high.
Accordingly, many studies have been performed to reduce the absolute amount of reflection of light made incident from the outside and to improve the scratch resistance of the surface, but the degree of improving the physical properties associated therewith is insufficient. In addition, a method of adding an inorganic additive or the like in order to improve the scratch resistance of a polymer film that is applied to the anti-reflective film, has been known. However, according to this known method, since the alkali resistance of the polymer film is greatly decreased, there was a limit that applying to the process for the production of a polarizing plate or the like is incompatible.